The first 150 years after 1492, year when the Europeans reached America, is known for the fast and steady decrease of the Native American population. According to several researchs and authors like Borah and Cook, the estimated decimation during the first 130 years of colonization was about of 95%.
According to historical research, the decimation was caused by the quick transmission of diseases like smallpox and syphilis. Also, the war against the conquerors and forced labours had an impact over the native population.
